An early morning power outage to almost 5,000 Newfoundland Power customers on Tuesday morning was caused by shots fired on a power transformer, says a utility spokesperson.

Michelle Coughlan, director of public affairs with NL Power, said vandals intentionally fired shots at one of the transformers at the Pulpit Rock substation in Torbay.

Customers in the area were without power from around 3 a.m. until shortly after 5 a.m. Tuesday as a result.

According to Coughlan, there is no news on how many shots were fired, but the incident is being investigated by the Royal Newfoundland Constabulary.

She said the damage to the transformer was serious.

"Currently, that transformer is extensively damaged and therefore out of service. Our crews are assessing to see whether or not the transformer can be repaired, or if indeed it will have to be replaced," Coughlan said.

On top of damages to the transformer, a large amount of oil was spilled as a result of the shots.

"There is oil contained within that power transformer that insulates or cools the transformer as it works, so approximately 8,000 litres of oil spilled as a result of the damage done," Coughlan said.

According to Coughlan, an environmental contractor has been brought to the site to conduct an assessment and find a way to deal with the oil spill.

She said the utility is in fact offering a reward of $5,000 to any individual with information that could lead police to the responsible parties.

"When we assess vandalism such as happened this morning and look at the serious nature, and not only how it impacted our customers in terms of an outage in the middle of a winter storm, and certainly the safety risks that are involved to our employees and contractors who have to go down there and make the repairs, as well as the environmental impact, it's quite a concern for us," she said.

Coughlan said anyone with information about the incident should contact the RNC or Crime Stoppers.